A 72-year-old man presented with a painless nonhealing ulcer on the glans penis as well as an erythematous rash on the dorsal aspect of the hands.He was uncircumcised, denied any risk factors for sexually transmitted diseases, and reported a 40-year monogamous relationship with his wife. Previous therapiesfor the penile ulceration included a 14-day course of dicloxacillin sodium and topical mupirocin calcium with a commercially available occlusive dressingwith a gellike consistency, which resulted in no improvement. The patient had been previously diagnosed as having chronic myelogenous leukemia and hadbeen taking hydroxyurea for the past 2 years. Both the rash on the dorsalaspect of the hands and the ulcerative lesion on the penis developed 18 monthsafter initiation of hydroxyurea therapy.